Glioblastoma with primitive neuroectodermal tumor-like features: case report.

Glioblastoma multiforme (GB) is the most aggressive, and the most frequent primary tumor of the brain in adults. Presence of less-differentiated areas which exhibit a small cell morphology and neural immunophenotype is quite uncommon in GBs. Tumor tissue which had been determined in the frontotemporal region of a 61-year-old female patient and evaluated to be consistent with GB radiologically was subjected to total excision. Histopathological examination revealed two different components making up the tumor tissue. Using a morphological and immunophenotypic approach, the predominant component of the tumor was found to bear the properties of classic GB. The other component was composed of undifferentiated areas exhibiting small cell morphology and diffuse neuronal immunophenotype. The case was diagnosed as 'Glioblastoma with primitive neuroectodermal tumor-like component'. The patient who had been subjected to postoperative radiotherapy, showed no sign of recurrence during the follow-up examination performed on the 9th month. The histogenesis and prognostic significance of neuronal differentiation observed in glial tumors are not known yet. Inclusion of this component in pathological reports is important regarding formation of a database for future studies.